This study is to compare tryptophan depleted and nondepleted groups and correlate within depressed subjects, the changes in : 49 hour lumbar CSF and plasma levels of indolamines, mood and behaviors. We will also analyze between groups to assess effects of tryptophan depletion in depression before and after antidepressant treatment. An addendum to this pilot was added to do sleep research to correlate CSF tryptophan amounts with sleep stages. This study is completed and data collected will be to submitted for additional support.